抄録
Sakai, Y., Ichikawa, S., Yoshida, M., Oouchi, M. and Miyagawa, M. ATPase Activity and Calcium Uptake of Microsomes Isolated from Stomach Smooth Muscle after Exposure to Phospholipase C. Japanese J. Smooth Muscle Res., 1982, 18, (5), 339-345. ATPase activity and Ca2+ uptake were examined in microsomal membrane fractions isolated from guinea pig stomach smooth muscle which had been exposed to phospholipase C (PLC). Basal Mg2+-ATPase, Na+, K+-ATPase and Ca2+, Mg2+-ATP activities were inhibited in a time dependent manner by PLC treatment. There was positive correlatioon between each of these ATPase activities and total phospholipid content of the microsomal fraction. Phosphotidylcholine restored Ca2+, Mg2+-ATPase activity of the microsomal fraction isolated from the tissue which had been treated with PLC for 30min but not after 60min. Ca2+ uptake in the presence of ATP by microsomal fraction from tissue treated with PLC for 60min was significantly decreased. The results provide a cellular basis for the inhibitory effect of PLC on contractility of stomach smooth muscle.
